1) Field of the Invention
The present invention relates to a method and apparatus for detecting a movement of a finger by performing pattern matching between a past fingerprint image and a current fingerprint image. More specifically, the present invention relates to a finger movement method and apparatus suitable to be applied to a pointing device for small portable equipment using a fingerprint image.
2) Description of the Related Art
Conventionally, an electronic track pad equipped in a notebook-sized personal computer has been known as a pointing device. The track pad, however, requires a sensor face larger than a fingertip for detecting the position of the fingertip, and hence it is not preferable for small portable equipment, such as a mobile phone. Recently, an authentication system using a fingerprint image has been put to practical use, and it can be considered to use the fingerprint image also in the pointing device.
An idea for realizing the pointing function by detecting a finger movement based on a fingerprint image has been already proposed.
However, any method of detecting a finger movement from a fingerprint image and any configuration of a pointing device realized by the method have not yet been proposed specifically. Further, in order to equip small portable equipment such as a mobile phone with the pointing device, it is necessary to reduce the size of the sensor face for detecting a fingerprint than the size of the fingertip. However, any method and apparatus for detecting the finger movement on the sensor face having such a small size have not yet been proposed.
Since the pointing device is used all the time, any pointing device using the fingerprint image requires high pointing accuracy and calculation load that is as small as possible.